STRUCTURE OF POLY-BIS-2,2,3,3,3-PENTAFLUO ROPROPOXYPHOSPHAZENE IN VARIOUS PHASE STATES

Samples of poly-bis-2,2,3,3,3-pentafluoropropoxyphosphazene, prepared by extrusion from the mesophase state, were studied by the methods of differential scanning calorimetry and X-ray diffraction in a wide rang e of temperatures. The structures of various phase states of the polym er were identified. The monoclinic and orthorhombic modifications of t he elementary cell were found for low-temperature and high-temperature crystalline phases, respectively. The existence of the condis-crystal line mesophase with pseudo-hexagonal packing, two-dimensional long-ran ge ordering in a plane perpendicular to the main-chain axis, and short -range ordering along the axes of conformationally disordered chains w as confirmed.